Strapping device for packing machine

ABSTRACT

A strapping device  1  for strapping flat objects stacked in bundles for a packing machine. A strap applicator attaches together the flat objects of each bundle. A first conveyor  60  moves each bundle from the entrance of the strapping device  1  to the strap applicator, and a second conveyor  70  moves each strapped bundle from the strap applicator to the exit of the strapping device  1 . The strap applicator is integrated into a standalone unit  10  which is independent of the first and second conveyor  70 , and which is mounted so as to be extracted from the strapping device  1.

The present invention relates to a device making it possible to attach together flat objects stacked in bundles and notably bundles of folding boxes.

The invention finds a particularly advantageous application in the packaging field.

In the packaging industry, the manufacture of folding boxes conventionally takes place on a line, by folding and gluing blanks by means of machines commonly known as folder-gluers. Usually, the folding boxes are delivered in the form of a continuous flow so that it is appropriate to pack them in bundles when said boxes are intended to be stored before their first use.

In this system, it is known practice to pack the folding boxes in the form of strapped bundles, that is to say stacks of boxes that are individually attached by means of one or more tying elements. Various types of strapping means may be used to accomplish this task, depending on whether it is desired for example to tie each bundle by means of at least one thin tying element such as a string, strap each bundle by means of at least one narrow tying element such as a flat band or to wrap each bundle by using at least one broad tying element such as a band.

At the industrial level, such a packing function is usually performed by a machine which is capable of forming bundles from the continuous stream of folding boxes which comes out of the folder-gluer, and then of tying together all the boxes of each bundle. The objective is to deliver a succession of strapped bundles which can then be easily palletized so that they can be handled and/or stored.

In practice, the packing process that is used consists initially in counting the boxes one by one so as to be able to separate them evenly when a clearly determined number is reached, and thus create a succession of batches of boxes. The process then continues with bundling which consists in forming the bundles by stacking in a more or less complex manner a small number of batches, usually two. The packing then continues with the strapping, an operation during which the boxes of each bundle are assembled together by means of one or more tying elements. The process finally ends with making each strapped bundle available in a dedicated reception area.

In fact, bundling is therefore a process which requires the application of a relatively large number of successive operations. This is why the packing machines of the prior art conventionally have a modular structure in which the various packing operations are distributed between several modules.

It is for this reason that, amongst the packing machines that are known from the prior art, there are those that use strapping means permanently incorporated into one of the modules; conveying means furthermore being installed both upstream and downstream of said strapping means in order to move the bundles through said module. Unfortunately, this type of arrangement has the drawback of making the packing machine particularly inflexible.

Because the configuration of the strapping module is fixed, it makes any change in the strapping means within said module impossible. This means that, if it is necessary to modify the type of tying element used when switching from one packing job to another, the operator is then forced to replace the module in its entirety. In practice, this involves making an exchange and therefore a double movement. In point of fact, because of their bulk and their respective weights, moving two strapping modules is clearly not an easy thing. The result is that this exchange operation will unavoidably require a prolonged shutdown of the folding box production line which is extremely disadvantageous in terms of productivity.

This being so, the fact that the strapping means are permanently incorporated into the module has other disadvantages. Specifically, this feature naturally tends to limit accessibility to the strapping means and therefore to significantly complicate any maintenance and/or repair operations. In both cases irrespectively, this also results in the obligation to stop production of the folding boxes for a long period.

Another category of packing machines with a modular structure is known in the prior art which does not pose this type of problem. This type of machine is noteworthy in that it uses strapping means that are incorporated into a movable and standalone apparatus which is designed to insert itself between two modules of said machine.

But unfortunately here also there is a major drawback which in this instance concerns the interfaces between this movable strapping apparatus and the two static modules that surround it. Since these three elements are structurally fairly independent, the transfer areas that join them are not optimized in terms of guidance. The practical result of this is that it is always difficult to transfer the unstrapped bundles from the upstream module to the strapping apparatus and then to transfer the strapped bundles from said strapping apparatus to the downstream module. It should be noted that this problem becomes more marked as the format of the folding boxes becomes complex.

Also, the technical problem to be solved by the subject of the present invention is to propose a device for strapping flat objects stacked in bundles for a packing machine, comprising strapping means for attaching together the flat objects comprising each bundle, first conveying means for moving each bundle from the entrance of the strapping device to the strapping means, and second conveying means for moving each strapped bundle from the strapping means to the exit of the strapping device, a strapping device which would make it possible to avoid the problems of the prior art by providing notably a substantially increased flexibility.

The solution to the technical problem that is posed consists, according to the present invention, in the strapping means being integrated into a standalone unit which is independent both of the first conveying means and the second conveying means and which is mounted so as to be extractable from the whole of the strapping device.

It is understood that the invention applies to any type of strapping means, whether the latter be capable of tying each bundle by means of at least one thin tying element such as a string, of strapping each bundle by means of at least one narrow tying element such as a flat band, of wrapping each bundle by using at least one broad tying element such as a band, or of individually attaching each bundle by any combination of tying elements of any type and of any dimension. This means in common terms that the strapping unit may be without distinction a binding machine, a strapping machine or a wrapping machine.

Whichever it is, the invention as defined has the advantage of providing very great flexibility.

Specifically, it first of all provides the option of replacing the strapping unit with another of a different type, depending on the packing job that has to be done. This makes it possible to select the strapping means most appropriate for the type and/or the shape and/or the dimensions of the flat objects to be packed, and notably to choose between tying, strapping or wrapping.

Furthermore, the invention makes it possible to replace the strapping unit with an equivalent unit. This feature naturally is of value in a breakdown situation since it makes it possible to rapidly replace a faulty unit with a fully functioning unit. However, it is also advantageous in the event of a maintenance operation because it allows repair work to be done outside the packing machine.

Finally, the invention provides the option of temporarily extracting the strapping unit from the packing machine for the purpose of using it manually in a totally independent manner.

The present invention also relates to the features that will emerge during the following description and which must be considered in isolation or in all their possible technical combinations.

This description, given as a nonlimiting example, is designed to make it easier to understand what the invention involves and how it can be embodied. Furthermore, the description is given with reference to the appended drawings in which:

FIG. 1 illustrates a strapping device which conforms to the invention and which is shown in working conditions, that is to say with the strapping unit positioned in said strapping device.

FIG. 2 is a view similar to FIG. 1, but with the strapping unit being extracted from the strapping device.

FIG. 3 shows in detail locking means which are fitted to the strapping device that is the subject of the invention.

FIG. 4 shows second conveying means with which the strapping device is also provided.

For reasons of clarity, the same elements have been indicated by identical reference numbers. Similarly, only the elements that are essential for understanding the invention have been shown, and this is done not to scale and in a schematic manner.

FIGS. 1 and 2 illustrate a strapping device 1 which is designed to be incorporated, in modular form, into a packing machine capable of transforming a continuous stream of folding boxes coming out of a folder-gluer in a succession of strapped bundles ready to be handled and/or stored.

As its name implies, the strapping device 1 is more particularly responsible for tying stacks of folding boxes which are formed completely upstream of said device, in this instance on an assembly table 2. The objective is to produce strapped bundles which will be made available at a delivery table 3.

In order to fulfill its function, the strapping device 1 has strapping means for attaching together the folding boxes comprising each bundle, a first conveying means 60 for moving each bundle from the entrance of the strapping device 1 to the strapping means, and second conveying means 70 for moving each strapped bundle from the strapping means to the exit of the strapping device 1. All of these elements are incorporated inside an enclosure 4 which is provided with a sliding access door 5 and which extends between the assembly table 2 and the delivery table 3.

According to the subject of the present invention, the strapping means are integrated into a standalone unit 10 which is independent both of the first conveying means 60 and the second conveying means 70 and which is mounted so as to be extractable from the whole of the strapping device 1.

As can be clearly seen by comparing FIGS. 1 and 2, the strapping unit 10 is mounted so as to be able to move between an internal position and an external position. The assembly is arranged so that, in the internal position (FIG. 1), the strapping unit 10 is capable of operating inside the strapping device 1, and so that, in the external position (FIG. 2), said strapping unit 10 is placed outside said strapping device 1.

It is understood that at this stage of the description, the strapping unit 10 is capable of being extracted from or inserted into the strapping device 1 without having its own means of movement. Thought is given notably here to a strapping unit 10 that is simply placed on roller wheels or rollers forming an integral part of the enclosure 4.

However, and according to a currently preferred embodiment of the invention, the strapping unit 10 in this instance comprises its own means of transport 20 in order to be able to move between the internal position and the external position. In this exemplary embodiment, these means of transport 20 consist of four wheels 21 which are mounted rotatably at the four corners of the strapping unit 10.

According to a particular feature of the invention, the strapping device 1 is furnished with guide means 30 which are capable of guiding the movement of the strapping unit 10 between the internal position and the external position.

In this exemplary embodiment, the guide means 30 comprise two internal guide rails 31, 32 which are attached inside the strapping device 1, and two external guide rails 33, 34 which are capable of being removably mounted outside the strapping device 1, substantially in line with the internal guide rails 31, 32. The assembly is moreover arranged so that the internal and external guide rails 31, 32, 33, 34 are capable of interacting directly with the means of transport 20 of the strapping unit 10. It is however understood in this instance that it is perfectly possible to design and use guide means 30 that are independent of the means of transport 20 specific to the strapping unit 10.

According to another particular feature of the invention, the strapping device 1 is also provided with centering means 40 which are capable of precisely positioning the strapping unit 10 inside said strapping device 1.

In this exemplary embodiment, the centering takes place at the four corners of the strapping unit 10 as can be seen in FIGS. 1 and 2. According to FIG. 3, it takes place by virtue of the presence of four pins 41 which are capable of being inserted in four positioning holes 42 arranged inside the enclosure 4.

According to another particular feature of the invention that can be seen in FIG. 3, the strapping device 1 also has locking means 50 which are capable of immobilizing the strapping unit 10 inside said strapping device 1.

In this exemplary embodiment, the locking means 50 consist of a single bolt 51 which conventionally consists of a screw 52 and a nut 53. In a conventional manner, this bolt 51 is engaged both through a first attachment hole 54 which is arranged in the enclosure 4, and through a second attachment hole 55 belonging to the strapping unit 10. Naturally, other attachment bolts 51 could be used, notably at the other corners of the strapping unit 10.

Because of the extractable character of the strapping unit 10, the latter has a relatively simple structure so as to remain easy to manipulate. It is for this reason that the strapping unit 10 logically has no conveying means capable of passing each bundle through it and it is the rest of the strapping device 1 which is fitted therewith, both with respect to the upstream portion and the downstream portion of the strapping unit 10.

Therefore, first conveying means 60 are provided to move each bundle from the entrance of the strapping device 1, and to bring it into the strapping unit 10. In the same manner, second conveying means 70 are also installed for extracting each strapped bundle from the strapping unit 10 and then conveying it to the exit of the strapping device 1.

In this exemplary embodiment, the structure and the operation of the first conveying means 60 are similar to those of the second conveying means 70. Also, for reasons of clarity, the first conveying means 60 are not fully represented in FIGS. 1 and 2, and only the second conveying means 70 will be described in detail.

According to a currently preferred embodiment of the invention, the second conveying means 70 consist in this instance of a conveyance member 71 which is operative up to inside the strapping unit 10, in this instance up to the area in which the strapping takes place. This conveyance member 71 is furthermore mounted so as to be able to move between an active position and a passive position. The assembly is arranged so that, in the active position (FIG. 1), the conveyance member 71 extends substantially in the plane along which the bundles travel in the strapping device 1 and so that, in the passive position (FIG. 2), said conveyance member 71 holds itself at a distance from the strapping unit in order to allow the free movement of the latter if necessary.

As can be seen more clearly in FIG. 4, the conveyance member 71 is mounted so as to pivot relative to an axis 72 which is transverse relative to the strapping device 1 and which is at a distance from the strapping unit 10. In practice, the conveyance member 71 takes the form of a conveyor belt 73 which is conventionally mounted movably between a drive shaft 74 coupled to an electric motor 75 and an idler roller 76 simply mounted rotatably.

In a particularly advantageous manner, the second conveying means 70 are furnished with locking means capable of immobilizing the conveyance member 71 in the active position (FIG. 1). Even though this is not visible in the various figures, in this exemplary embodiment, the locking means in question consist of a simple pin.

According to another advantageous feature, the second conveying means 70 are furthermore provided with assistance means 77 which are capable of driving the conveyance member to the passive position (FIG. 2). As can be seen in FIG. 4, the assistance means 77 of this exemplary embodiment consist of two gas cylinders 78 which are installed on each side of the conveyance member 71 and which act to push said conveyance member 71 away from its active position, that is to say toward the passive position.

Naturally, the invention relates more generally to any machine for packing flat objects notably of the folding box type, which comprises at least one strapping device 1 as described above. 

1. A strapping device for strapping flat objects stacked in bundles for a packing machine, the strapping device comprising: the strapping device having an entrance for a bundle of flat objects and an exit for strapped bundles of the objects; a strap applicator for strapping together a plurality of the flat objects for producing each bundle; a first conveyor configured and operable for moving each bundle from the entrance of the strapping device to the strapping applicator; a second conveyor configured and operable for moving each strapped bundle from the strap applicator to the exit of the strapping device; a standalone unit into which the strap applicator is integrated, the unit is independent of both the first conveyor and the second conveyor and is so mounted and positioned in the strapping device and so configured as to be extractable from the entire strapping device.
 2. A strapping device according to claim 1, wherein the standalone unit is mounted in the strapping device to be moved between an internal position, in which the standalone unit and the strap applicator operate inside the strapping device, and an external position, in which they are outside the strapping device.
 3. A strapping device according to claim 2, wherein the standalone unit comprises a transport device configured to move the standalone unit between the internal position and the external position.
 4. A strapping device according to claim 2, further comprising a guide configured for guiding movement of the standalone unit between the internal position and the external position.
 5. A strapping device according to claim 4, wherein the guide comprises: at least one internal guide rail attached inside the strapping device, and at least one external guide rail removably mounted outside the strapping device; each external guide rail is substantially in line with a respective internal guide rails; both of the internal and the external guide rails are configured to interact directly with the transport device of the strapping unit.
 6. A strapping device according to claim 1, further comprising a centering device configured for positioning the standalone unit inside the strapping device.
 7. A strapping device according to claim 1, further comprising a locking device configured for immobilizing the standalone unit inside the strapping device.
 8. A strapping device according to claim 1, wherein at least one of the conveyors comprises a bundle conveyance member, which is operative to convey bundles of the objects up to inside the standalone unit and which is mounted and configured for moving between an active position, in which the conveyance member extends substantially in a plane along which the bundles travel in the strapping device, and a passive position in which, the conveyance member is at a distance from the standalone unit in order to allow movement of the unit.
 9. A strapping device according to claim 8, wherein the conveyance member is mounted to pivot relative to an axis thereof which is transverse relative to the strapping device and which is at a distance from the standalone unit.
 10. A strapping device according to claim 8, wherein the conveyor comprises a locking device configured for immobilizing the conveyance member in the active position.
 11. A strapping device according to claim 8, wherein the conveyor comprises an assistance device configured and operable for driving the conveyance member to the passive position.
 12. A machine for packing flat objects of the folding box type comprising at least one strapping device according to claim
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